[Swan] pfkey_x_kmprivate_build() oddity?

[D. Hugh Redelmeier]

Coverity Scan highlights this:

        struct sadb_x_kmprivate *pfkey_x_kmprivate = (struct sadb_x_kmprivate *)*pfkey_ext;

        /* sanity checks... */
        if(pfkey_x_kmprivate) {
                DEBUGGING(PF_KEY_DEBUG_BUILD,
                        "pfkey_x_kmprivate_build: "
                        "why is pfkey_x_kmprivate already pointing to something?\n");
                SENDERR(EINVAL);
        }

        pfkey_x_kmprivate->sadb_x_kmprivate_reserved = 0;

At the point of the sanity check:
if pfkey_x_kmprivate is non-NULL, we complain and exit (SENDERR).
if it is not, we immediately dereference it, a NULL pointer.

What's up with this?

Has this code ever worked?  (Of course I might be confused at 1 AM.)

Test case?

Blame says
	Michael Richardson 2005-11-02 13:10:32 
but this might well have been a mass-import from some other repo.
There are no more recent fingerprints nearby.